1. Technical Field
The present application relates to a wavelength conversion element including a phosphor layer, a light emitting device including the wavelength conversion element, and a vehicle including the light emitting device.
2. Description of the Related Art
A light emitting diode (hereinafter called “LED”) comprising semiconductor made of aluminum nitride (AlN), gallium nitride (GaN), indium nitride (InN) and mixed crystal thereof can emit light in a broad wavelength range from ultraviolet to infrared by adjusting the components of the semiconductor.
For example, a non-patent document (Shuji Nakamura et. al., Jpn. J. Appl. Phys. Vol. 34 (1995) L. 1332-L. 1335) discloses an LED element on the market, which emits visible light.
Patent documents (Japanese Patent Application Laid-open Publication Nos. 2009-200207, 2006-179618 (in particular, paragraph 0020), and 2005-191326 (in particular, paragraph 0056)) disclose LED elements that emit light in a blue wavelength region.
This kind of an LED element emits white light by mixing blue light from the LED element and yellow light from a wavelength conversion element that is excited by the blue light and emits the yellow light. For example, a patent document (Japanese Patent Application Laid-open Publication No. 2005-039264 (in particular, paragraph 0080)) discloses a white light emitting device of so-called remote phosphor type including a wavelength conversion element and an LED element. The wavelength conversion element comprises phosphor particles and transparent resin, and is located apart from the LED element.